Projector lamp



Nov. 13, 1928. 7 1,691,475

T. HALL PROJECTOR LAMP Filed Jan. 18, 1928 2 Sheets-Sheet 1 INYENTOR 72. 4am Hall Nov. 13, 1928. 1,691,475

T. HALL PROJECTOR LAMP Filed Jan. 18, 1928 2 Sheets-Sheet 2 INVENTOR Tfieoa'ore Hall THEODORE HALL, OF NEW YORK, 11'. 35., 'lC HALL & OONNOLLY, INCL, OF NEW YORK, N. 'Y., A CORPORATION OF NEW YORK.

PROJECTOR LAMP.

Application filed January 18, 1028i swarm). 247,527. r

This invention relates to illuminating apparatus and has special reference tohigh intensity fiaming are light projection devices wherein a source of light is projected through a lens and provisionis made for varying the projected light from a beam, or small spot-light, to a flood-light dispersion.

In this type of projecting device, employing the high intensity or other flaming arc, there is distort-ion oi the beam spot or floodlig'ht due to the long bright tail-flame and bright tip of the negative carbon being pro-.

jected in additionto the desired projection of the real or main light source, i. e., the positive crater. The image of the arc tailflame and that of'the negative carbon .tip are outside the true optical axisof the positive crater and the collectorlens, and can, therefore, .be interrupted at some point between the collector lens .and the secondary or obj ective lens, by interposing .a diaphragm and so designinglthe opening or aperture as to allow only the image of the positive crater, or some portion thereof to .be transmitted. But in order :to vary the size of the projected-beam :it is'necessary to vary the openingof the aperture of the diaphragm, Since this opening must be varied, the ,cone of light must also be adjusted so as to fill the largest diaphragm opening. Otherwise, ,when the opening is reduced, with the'cross section of the cone remaining the same, the

light projected through the objective lens is too greatly reduced forkeflicient operation.

One purpose of the invention is to devise an automatically operated arrangement which maintains the size of the light cone where it passes through the variable aperture in :the shutter of the propersize to .enable the maximum amount of flight .to be transmitted under all conditions and at the same time to .cut .out the .atoresaidundesirable light from the tail flame and negative tip. This is accomplished preferably by.

making the light source and collector lens relatively adjustable toward and away from each other, and while keeping the position of the shutter fixed, automatically varying .the size of the aperture as the beams cross section astheshutter varies.

Another object of the inventionis to provide for simultaneous adjustment of the position of the objective lensto obtain a greater range of spread than is now possible Without changing lenses. Still further objects of the invention will be apparent as the description proceeds.

Referring to the drawings'in which severalpreterred forms of my invention are snown:-- v

1 is a side elevation, partly in section, of my projector lamp, the usual housing being largely omitted.

Fig.2 is a corresponding view of another form of projector lamp.

Fig 3 is a vertical section taken approximately on line 33 of Fig. 2. I

Fig. l'is a detail section showing the slidable torque transmitting connection between the shafts used for transmitting the adjustments. I

In the drawings, an arc lamp mechanism, preferably of the high intensity flaming arc type, is shown generally at 1, the positive electrode 2 being shown as supported for rotation and forward feeding within the holder 3 with its crater 3, containing the principal V light source facing the collector lensese or other torm ot' condenser. The negative electrode .5 is shown positioned at an angle with its tip below the principal cone of light; That portion of the flame outsideof the ball of light .at' .the positive crater may be referred to generally as the tail flame and is of relatively low intrinsic ,brilliancy, but appears inverted in the beam unless cut out by a screen. I

In this torm'of the invention, thecollector and screen are made stationary and the light source moved to change the beam spread. As shown the collector lenses are mounted at the .front of the lam housing .6, vwhile the lamp mechanism is s idably mounted on a rod or rods 7, one foot 8 of ;the base '9 thereof being threaded on the rodso .that

rotation of the rod'by thumb piece 10 adjuststhe arcbackand forthas desired. Said rod .is shown as journaled in alugor lugs 11 on the lamp housing and has an .extension .12 projecting beyond the lamp housing to the screen 13. g

.Said screen is shown as in theform of an iris shutter mounted in frame-work 14 ad justably clamped on parallel rods 15 but normally locked in position by set screw 16. Adjustment of the size of the sport the shutter is secured in the usual manne rotation of annular gear 17 (Fig. 3) and this is accomplished automatically when the light source is adjusted by a drive connection between shaft 12 and said gear. As shown,

this may comprise a vertical shaft 18 having a bevel gear connection 19 wlth squared sleeve 44: on shaft 12, and having an exten- It is also undesirable to have the beam when contracted to a spot too intense and this condition is avoided by having the lamp furthest away from lens a when the opening in the shutter is smallest.

Preferably means are provided for disengaging gears '19, so that the iris shutter can be adjusted independently of the light source for internal setting and the like. For this purpose, I have shown shaft 18 as di vided into; two parts with a bayonet slot and'pin connection 25. lVhen the operator desires to so adjust the'shutter he first pushes up thumb piece 26, thus compressing spring 27 and disengaging the gears and then turns said thumb piece to, rotate the shaft lS. I When released by the operator, spring 27 re turns the gears into mesh.

also show means for ad usting thepos tion of the objective lens lO, since this is highly desirable if the maximum beam spread is to be obtained without changing lenses. l n Fig. l, a hand adjustment is shown for tnis pur pose comprising a shaft 28 journalei at in bracket 14 and having its outer end threaded in a lug 29 extending downwardly from the carria e 30 for the lens, said carria e bein t: i 0 O slidably mounted on rods 15.

' In Fig. 2, the relative ad ustment of the light source and collector lens is secured by adjusting the lens and providing a connec tion between it and the shutter. The lens carriage a is slidably mounted on rods 8i and threaded on a rotatable rod Said" rod has a driving connection with bevel gears 19 which adjust through shaft 18 and gears 20,21 the iris shutter 13.

For independent adjustment of the lens and shutter, I have shown shaft 3211s divided intotwo parts 321and 32", normally connected by a coupling 4:1, the two parts of the cou-,

pling being normally pressed together by spring 42. vVhen independent adjustment is desired, the operator grabs the thumb piece 43 and pushes forwardly on the same to co1npress the spring and detach the coupling. He then either turns the thumb piece 4L3 or the handle 10 as desired. There is also shown a slip coupling on the shaft 32 with the gear 33 to permit adjustment of the can riage 1d of the shutter. This connection is shown in detail in Fig, 4, shaft 32 being squared and gear 33 having a squared sleeve a l thereon which slidably but non rotatably fits on the shaft.

In this form also, I have shown automatic means for adjusting the position ofthe ob ective with changes in the beam. 'From shaft 32 as by gears 33, 3a and 35 I drive a shaft 36, which like shaft 28, has its end threaded in the lens bracket 30. By this means the objectivelensisalso positioned automatically in the proper position to 0b tain the'maximum amount of light onfthe 7 scene for dillereut beam spreads and without the necessity for changing lenses or separately adjusting by hand the position ofthe For independently ad usting the adjusted, if desired, by having the base 9 thereof threaded on the shaft 12 having knob 10 but this is ordinarily not-touched during a performance when quick adjustments are secured by means of the handle 10. If desired, I may also provide a shield or enclosure for the cone of light between the collector and shutter to further out out stray our .;,1.JY-? light. tines a sh eld is shown in Big. 1.

as comprising a pair of telescoping truncated hollow cones 45' and 46, one secured to 'hous-.

ing 6 and the other to frame 14;.

"By my invention it is possible to change quickly from a concentrated spot light to a full flood light While retaining the desired amount of illumination on the scene and at electrode shadow or'ima-ge.

In accordance with the provisions of the patent statutes, I have herein described the principle and operation of my invention together with the apparatus which I now consider to represent the best embodiment thereof, but I desire to haveit understood that the apparatus shown isionly illustrative and that the invention can be carried-out by other means. Also, while it is designed to lie use the various features and elements in the combination and'relations described, some of these may be altered and others omitted without interfering with the more general results outlined, and the invention extends to such use.

Having described my invention what I claim and desire to secure by Letters aper- V so I 2. In a flaming arc projector lamp, an arC lamp mechanism, a beam collector, an objective lens, a shutter adjustable to various size apertures positioned in the beam, means for changing the relative position of the arc and said collector, means interconnecting said first-named means and said shutter for adjusting the size of the aperture in said shutter accordingly, and additional means for independently adjusting the size of said aperture.

3. In a flaming arcprojector lamp, an arc lamp mechanism, a beam collector, an objective lens, a shutter adjustable to various size apertures positioned in the beam, means for changing the relative position of the arc and said collector, and means interconnecting said first-named means and said shutter for adjustingthe size of the aperture in said shutter and for varying the relative position of said objective lens.

4. In a flaming arc projector lamp, an arc lamp mechanism, a beam collector, an objectivelens, a shutter adjustable to various size apertures positioned in the beam,

means for changing the relative position of r the arc and said collector, meansinterconnecting said first-named means and said shutter for adjusting the size of the aperture in said shutter accordingly, additional means for independently adjusting the size of said aperture, and means for varying the relative position of said objective lens.

5. Ina projector lamp, an arc lamp mechanism, a collector lens, means for adjustably mounting said lens, an objective lens, an iris shutter or the like between said lenses, means for adjustably mounting said objective lens, and means interconnecting said lenses and shutter to adjust all simultaneously.

6. In a flaming arc projector lamp, an arc lamp mechanism, a beam collector,'an

objective lens, a shutter adjustable to vari- ,for adjustably mounting said objective lens,

means interconnecting saidlenses and shutter to adjust all simultaneously, and means for also adjusting said lenses andv shutter independently.

8. In a flaming arc projector lamp, an arc lamp mechanism, a beam collector, an

objective lens, a'shutter adjustable to various size apertures positioned in the beam, means for changing the relative position of the arc and said collector, means interconnecting said first-named means and said shutter for adjusting the size of the aperture in said shutter inaccordance with the divergence of the beam, and means for also adjusting the relative position of said objective lens.

9. In a projector lamp, the combination with an adjustably mounted source of light, an adjustably mounted collector, a shutter with a variable size aperture and an adjustably mounted objective, of means interconnecting said collector, shutter andobjective whereby the size of the aperture in the shutter and the position of the objective are automatically adjusted with adjustment of saidcollector.

In testimonywhereof I have aifixed my signature.

THEODORE HALL. 

